To provide an information recording medium recorded with an information signal of a structure which is relatively easily made longer in the maximum burst error length without increasing redundancy.

The information recording medium has a step of forming an ECC block composed of main data relating to main information on a prescribed number of words, auxiliary information including a sector address etc., and a parity by a product code system and a step of determining a continuous N piece (n≥2) among the ECC blocks as one set and outputting signals while interleaving by each (k+1)th line is successively switched after each k-th row of each ECC block is successively switched and outputted in such a manner that each first row of the one set of each ECC block is successively switched and outputted and thereafter each second row is successively switched and outputted. The information recorded medium with the information signal of the structure added with a frame synchronization to the signal outputted under interleaving is provided.